Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
  • C08G63/12—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/10—Esters; Ether-esters
  • C08K5/11—Esters; Ether-esters of acyclic polycarboxylic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F18/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an acyloxy radical of a saturated carboxylic acid, of carbonic acid or of a haloformic acid
  • C08F18/02—Esters of monocarboxylic acids
  • C08F18/04—Vinyl esters
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F22/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals each having only one carbon-to-carbon double bond, and at least one being terminated by a carboxyl radical and containing at least one other carboxyl radical in the molecule; Salts, anhydrides, esters, amides, imides or nitriles thereof
  • C08F22/10—Esters
  • C08F22/1006—Esters of polyhydric alcohols or polyhydric phenols, e.g. ethylene glycol dimethacrylate
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
  • C08G63/12—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
  • C08G63/16—Dicarboxylic acids and dihydroxy compounds
  • C08G63/20—Polyesters having been prepared in the presence of compounds having one reactive group or more than two reactive groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L101/00—Compositions of unspecified macromolecular compounds
  • C08L101/02—Compositions of unspecified macromolecular compounds characterised by the presence of specified groups, e.g. terminal or pendant functional groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins

Definitions

• the invention relates to use of a branched polyester as a de-foaming agent and as an internal release agent.
• the invention further relates to a curable pre-polymer composition.
• de-foaming or anti-foaming agents are known A defoamer or an anti-foaming agent is a chemical additive that reduces and hinders the formation of foam in industrial process liquids.
• de-foaming agent and anti-foaming agents are often used interchangeably.
• Commonly used de-foaming agents are insoluble oils, polydimethylsiloxanes and other silicones, certain alcohols, stearates and glycols.
• De-foaming agents based on small scale particles like ureas are known as well.
• the additives are generally used to prevent formation of foam or they are added to break a foam already formed.
• de-foaming agents and compositions are often costly and the use of de-foaming agents contributes to the overall costs of curable pre-polymer compositions.
• de-foaming agents also increases the complexity of the overall recipe of curable pre-polymer compositions and the risk of unpredictable interactions between components.
• branched polyester having an average of at least 2.8 terminal groups can be used as de-foaming agent in curable pre-polymer compositions.
• the branched polyester is relatively cheap and does not significantly contribute to the overall cost of the curable pre-polymer composition, yet it acts as a de-foaming agent and it improves the release of entrapped gas bubbles in curable pre-polymer formulations.
• the branched polyester has an average of at least 2.8 terminal groups.
• Branched polyesters can be prepared by generally know methods using building blocks having an average functionality of ester-forming functional groups exceeding 2.0.
• suitable building blocks include polyols, polyacids, and building blocks having carboxylic acid and hydroxyl functionality.
• Suitable polyols include glycerol, trimethylol propane, di-trimethylol propane, pentaerythritol, and di-pentaerythritol.
• Suitable polyacids include citric acid, aconitic acid, trimesic acid, and trimellitic acid. Anhydrides and lower alcohol esters of the aforementioned compounds can be used as well.
• Dimethylol propionic acid is an example of a building block having two hydroxyl groups and one carboxylic acid group.
• the usage of higher functional building blocks determines the degree of branching and thus the number of end groups of the branched polyester.
• the branched polyester has an average of at least 3.1, and more preferably at least 3.5 end groups.
• the branched polyester has an average of at most 7.0 end groups.
• the polyester has an average of at most 6.0 end groups.
• the branched polyester has an average number of end groups in the range of 3.5 to 5.5.
• the branched polyester is used as an additive in a curable pre-polymer composition.
• Curable pre-polymer compositions are liquid or viscous compositions comprising polymer precursors, for example monomers and/or oligomers having functional groups capable of chemical curing reactions.
• the chemical curing reactions lead to an increase in molecular weight to transform the polymer precursors to polymers.
• crosslinked polymers are formed by the curing reaction.
• the branched polyester acts as a de-foaming agent in the pre-polymer composition.
• the branched polyester leads to a lower degree of air entrapment in the pre-polymer composition and to a quicker release of gas bubbles which may be entrapped in the liquid pre-polymer composition during processing.
• the branched polyester exhibits a twofold effect in the pre-polymer composition and acts as an internal release agent and as de-foaming agent.
• a single additive provides two beneficial functions in the pre-polymer composition.
• a release agent provides parting properties between a mold and a part being molded.
• An internal release agent is an additive which is included in a pre-polymer mixture before being molded and/or cured.
• a release agent reduces the adhesion between the polymer part formed and the internal surface of the mold.
• a release agent facilitates separation of the formed part from the mold. This prevents damage of the surface of the formed part. Additionally, release agents can make the production line faster, more economical and more profitable.
• Internal release agents are frequently used in the production of sheet molding compounds, bulk molding compounds, and pre-polymer compositions which are compression molded in metal dies. Also, many injection molding and infusion operations make use of internal release agents. Typical release agents used for all these applications mentioned are salts of stearic acid but also linear fatty alcohol ethoxylate phosphates.
• a proportion of the terminal groups of the branched polyester used according to the invention is terminated by hydrocarbyl groups having from 8 to 40, preferably 10 to 30, carbon atoms. Typically, at least 50%, preferably at least 70% of the terminal groups are terminated by such hydrocarbyl groups. It is possible that substantially all or all terminal groups of the branched polyester are terminated by hydrocarbyl groups having 8 to 40 carbon atoms. Alternatively, at most 95%, or at most 90% of the terminal groups are terminated by hydrocarbyl groups having 8 to 40 carbon atoms.
• the hydrocarbyl groups may be aliphatic or aromatic, and they may be or comprise linear, branched, or cyclic groups.
• the hydrocarbyl groups may be saturated or unsaturated.
• the hydrocarbyl groups contain one or more ethylenically unsaturated groups.
• the terminal hydrocarbon groups comprise the residues of fatty acids and/or fatty alcohols having 10 to 30 carbon atoms.
• the branched polyester used according to the invention generally has a number average molecular weight Mn in the range of 1200 to 15000.
• Mn of the branched is at least 1500, or at least 1700.
• the Mn does not exceed 12000, or 9000.
• the Mn ranges from 1600 to 10.000.
• the polydispersity (weight average molecular weight divided by number average molecular weight) of the branched polyester generally ranges from 1.8 to 6.0.
• the polydispersity is in the range of 2.4 to 4.8.
• the molecular weight is expressed in g/mol and suitably determined by gel permeation chromatography, using tetrahydrofuran as eluent and polystyrene as calibration standard.
• the branched polyester is added to the pre-polymer composition in an amount of 0.1 to 15.0% by weight, calculated on the weight of the total pre-polymer composition.
• the amount of branched polyester in the pre-polymer composition is at least 0.5, preferably at least 1.5, and most preferred at least 2.5% by weight, for example 3.0 or 4.0% by weight.
• the amount of branched polyester in the pre-polymer composition does not exceed 12.5, preferably 10.0% by weight.
• the branched polyester is preferably provided as a liquid. Depending on the building blocks and molecular weight of the branched polyester, this material may have a sufficiently low viscosity as such to allow easy mixing of the branched polyester and the pre-polymer composition.
• the branched polyester is provided as a solution in an organic solvent.
• the solvent is a non-volatile solvent.
• Non-volatile solvents generally have a boiling point above 250° C., preferably above 300° C. at atmospheric pressure. Examples of suitable solvents include esters or mixtures of esters having a sufficiently high boiling point.
• a specific example of a suitable solvent is isotridecyl stearate.
• the amount of solvent used depends on the viscosity reduction required. Generally, the amount of solvent is in the range of 8 to 50%, more specifically 12 to 28% by weight, calculated on the amount of branched polyester.
• the curable pre-polymer composition is a liquid or viscous composition comprising monomeric or oligomeric molecules having functional groups.
• the functional groups are capable of chemical reactions to increase the molecular weight of the monomeric or oligomeric molecules. These reactions thus lead to a cured polymer which generally is solid.
• the cured polymer may be crosslinked or non-crosslinked.
• the chemical reaction of the functional groups may be triggered in various ways.
• the curable pre-polymer composition is provided as a two- or more component composition, wherein the components comprise mutually reactive functional groups which are mixed prior to use.
• the components comprise mutually reactive functional groups which are mixed prior to use. Examples include epoxide groups, which are reactive with amine groups, hydroxyl groups, or carboxylic acid groups; isocyanate groups which are reactive with amine, hydroxyl, or thiol groups; and electron deficient ethylenically unsaturated groups which are reactive with amine groups or thiol groups.
• the functional groups are radically polymerizable functional groups.
• the curing reaction is a radical polymerization reaction which can triggered by radical generating initiators, such as peroxides, or by actinic radiation, such as UV radiation or electron beam radiation, or by combinations thereof.
• the curable pre-polymer composition comprises an unsaturated polyester base and a polymerizable monomer diluent, such as styrene or an acrylic or methacrylic monomer.
• the curable pre-polymer composition may comprise other ingredients which are typically present in such compositions.
• ingredients include organic or inorganic particulate fillers, pigments, dispersants or dispersing aids, stabilizers, such as UV stabilizers, and fibers.
• the invention further relates to a curable pre-polymer composition
• a curable pre-polymer composition comprising a curable pre-polymer and a branched polyester having an average of at least 2.8 terminal groups, wherein the terminal groups comprise the residues of fatty acids and/or fatty alcohols having 10 to 30 carbon atoms.
• the branched polyester is present in an amount of 2.5 to 15.0% by weight, calculated in the weight of the curable pre-polymer composition.
• the composition further comprises a solvent having a boiling point above 250° C. at atmospheric pressure.
• the invention also relates to a process of simultaneously improving the release properties and the de-foaming characteristics of a curable pre-polymer composition comprising a curable pre-polymer, comprising the step of adding to the curable pre-polymer composition a branched polyester having an average of at least 2.8 terminal groups.
• Part A of a system (listed in Table 4 as Part A) was added the test substance (amount and description: see Table 4). The mixture was stirred by hand until the mixture was homogeneous. Afterwards, Part B of a system (listed in Table 4 as Part B) and Part C of a system (listed in Table 4 as Part C) was added. This mixture was stirred using a dissolver (Pendraulik TD 100, Dissolver plate diameter: 40 ⁇ 10 mm) for 60 seconds ⁇ 10 seconds with a speed of 2800 rpm ⁇ 250 rpm to homogenize and to create foam.
• a dissolver Pendraulik TD 100, Dissolver plate diameter: 40 ⁇ 10 mm
• the two sheets were removed and panels of 10 ⁇ 10 cm were cut out of the material.
• the panels were rated by comparing the total amount of air bubbles entrapped in the panel with marks from 1 (very good defoaming properties, nearly no bubbles entrapped) to 5 (poor defoaming properties, many air bubbles entrapped).
• the hoses were sealed on the in- and outlet with a plug and the entire mold with hoses was placed in a convection oven to cure the panel for 10 h at 80° C.
• the force needed to demold the panel was rated with marks from 1 (very easy demolding, no force needed) to 5 (poor demolding, fracture in the panel during demolding).
• the branched polyesters used according to the invention in Examples 37 to 48 are very effective as internal mold release agents. They are effective when used in small amounts and provide equal or better mold release properties than known internal release agents used according to comparative Examples 49 to 52. Thus, the branched polyesters have a twofold beneficial effect, because they act as mold release agent and as de-foaming agent when used according to the invention.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Polyesters Or Polycarbonates (AREA)
• Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)

Applications Claiming Priority (4)

Publications (2)

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• 2018
  • 2018-08-20 ES ES18752792T patent/ES2890708T3/es active Active
  • 2018-08-20 US US16/639,797 patent/US11248105B2/en active Active
  • 2018-08-20 WO PCT/EP2018/072402 patent/WO2019038216A1/en not_active Ceased
  • 2018-08-20 CN CN201880053970.4A patent/CN111032725B/zh active Active
  • 2018-08-20 EP EP18752792.4A patent/EP3673002B1/en active Active

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